Peppermint shrimp eating star polyps?

Well yesterday I added a peppermint shrimp(yes it for sure is) to my tank. I carefully looked at it before I bought it. According to online websites they are reef safe so I got it. I've noticed it picking at my green star polyps so I went out and bought shrimp to feed it. Yea I know shrimp eating shrimp sounds da bad but he loves it. So I figured that would solve my problem. Nope. Still picking at it. Will it kill it? And what should I do?